chore(core): add publish guards and auto-publish workflow

[harishsundar-okta]

Summary

Adds automated version parity enforcement, pre-flight publish guards, and an auto-publish workflow to eliminate manual publish steps and prevent version drift between core and react packages.

Why

The current npm publish process has three gaps: publishing is manual-only (risk of forgetting or publishing stale versions), there's no early check for duplicate versions on npm (wasting CI time before failing), and nothing prevents core and react package versions from drifting apart (causing broken consumer installs).

What

• ci-cd.yml — Added a Verify core/react version parity step that runs before install/build, failing PRs immediately if package.json and package.json have different versions.
• publish-public-npm.yml — Added a Pre-flight version and registry check step before pnpm install that verifies version parity and checks if either package version already exists on npm (skipped for dry runs).
• auto-publish.yml — New workflow triggered on pushes to main that touch either package.json. Compares the version field against the previous commit, enforces parity, and triggers the existing publish workflow. Non-version changes (e.g., dependency updates) are ignored. Manual workflow_dispatch remains as a fallback.

Packages

• packages/core
• packages/react
• examples

References

Testing

• 

Checklist

• Breaking change
• Requires docs update
• Backward compatible

Contributing

• I have read the Auth0 general contribution guidelines
• I have read the Auth0 Code of Conduct

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.41%. Comparing base (0aea0b1) to head (f65a4b7).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #285   +/-   ##
=======================================
  Coverage   89.41%   89.41%           
=======================================
  Files         159      159           
  Lines       13334    13334           
  Branches     1828     1750   -78     
=======================================
  Hits        11923    11923           
  Misses       1411     1411           

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